Learnings

Outcomes

The project identified mechanisms which are most likely to be a cause for concern for increased likelihood of ignition with a transition to hydrogen. A programme of work has been identifed for further testing to fill the gaps identified in this project. Stage 2 will look to address remaining gaps relating to static generation from particulates in flowing gas, shockwave ignition and ignition from rapid adiabatic compression. 

Lessons Learnt

While there is a great deal of theoretical evidence covering proposed ignition mechanisms there was very little work done to directly compare or measure situations which would be realistic to the gas industry when considering both Natural Gas and hydrogen. The lower minimum ignition energy (MIE) of hydrogen has been a cause for concern, however the work conducted by Steer Energy highlights the fact that gas concentrations for hydrogen need to be at high concentrations (29% GIA) to facilitate this MIE. Both gases are more challenging to ignite than perceived, however the lower MIE of hydrogen does illustrate that it may be easier to ignite given specific circumstances. This point mandates further testing to establish the real-world risk of Hydrogen. 

The findings from stage 1 of HIRSA have allowed Steer Energy to develop a testing plan to address the highest risk areas. This testing plan will be executed over the coming months in a stage 2 of the project to ensure that evidence gaps are filled with robust evidence and provide the HSE with appropriate evidence for their policy decision on hydrogen for heating. 

Stage 2a will explore the impact on static generation caused by particulates in flowing gas at different velocities, and with different gas compositions (100% Natural Gas, a 20% hydrogen blend with Natural Gas, and 100% hydrogen). This work has been expedited to ensure the testing can be done in line with the Velocity Design with Hydrogen project. 

Stage 2b will explore the remaining 2 mechanism (shockwave ignition, and rapid adiabatic compression) and how they might impact the transition to 100% hydrogen on the LTS and NTS.